Treatments to retard the growth of facial hair in hirsute females through medication are not practiced in many countries. When such treatment is given, its effectiveness can be accurately assessed only through objective measurement of changes in the rate of hair growth. Many methods used for that measurement lack the necessary accuracy and reproducibility of results. Subjective results from direct examination are largely influenced by expectance levels of both the doctor and the patient, while the examination of photographs taken before and after treatment has been found to lack sensitivity to small fluctuations in the growth rate.
Two methods have been proposed for objective measurement of the rate of hair growth. One involves taking measurements of hair length at selected intervals of time by fitting a graduated capillary tube about a growing hair and gently pressing the end of the tube to the surface of the skin. The image of the hair in the capillary tube is then magnified 16 to 25 times by a Zeiss dermascope for comparison of the hair length with the graduations. However, this method requires the use of sophisticated equipment which is very expensive. Such equipment is also difficult for one operator to handle when used in conjunction with a capillary tube. A second method involves the injection of radioactive sulphur (S.sup.35). However, this method invades healthy tissue and requires facilities for counting radioactivity. Each of these objective methods is restricted to specialized units due to the nature of the materials and equipment required.
With the aforementioned limitations and deficiencies of known devices in mind, it is an object of the present invention to provide a novel apparatus for accurately measuring the growth rate of hair. More particularly, it is an object to provide an inexpensive and portable apparatus to measure the growth rate of hair which will yield accurate and reproducible results in the hands of technicians of limited training and experience.
Another object of the invention is to provide such an apparatus which may be operated by a single technician.
Yet another object is to provide such a device which includes a graduated tubular member and a light source in which the latter performs the dual function of projecting illumination into the tubular member and also supporting said member.
It is a further object of the invention to provide a simple yet reliable device for the repetitive location of a sample area on a body whose hair growth rate is to be monitored, to enable length measurements to be taken of the hairs in that area at different times.
We have discovered that the above objects and advantages are achieved by a graduated capillary tube or like transparent member having an open end adapted to be placed about a hair to be measured and illuminated with substantially axially directed light for visual comparison of the longitudinal extent of the hair with the graduations. A series of hair length measurements can be made with this instrument at selected intervals of time to determine the growth rate. The capillary tube may have a flattened region in the area of the graduations to enable those graduations to be more easily read. The tube may also be provided with a passage communicating between the atmosphere and the opening into which the hair is received to facilitate the introduction of a liquid such as water into that opening. The presence of the liquid further enhances the readability of the instrument. It is to be understood that when we refer to the tube as being transparent, we mean that the material is sufficiently clear so that a hair can be viewed through it when the tube is illuminated.
The particular area of the body at which the growth rate is to be measured can be repetitively and accurately located with a mechanism which includes two perpendicular arms adjustable relative to each other along their respective axes and having graduations indicating their precise adjustment. One of said arms is adapted to be placed against a suitable reference point on the body while the other has an opening which defines the area of the body where a measurement is to be taken.